In order to run a successful basic oxygen furnace--continuous slab caster combination there is a need for low sulfur blast furnace hot metal. It has been found that by introducing magnesium into a ladle that the sulfur content of the hot metal may be reduced. This is typically done by mixing finely powdered magnesium with small quantities of powdered lime, and then entraining the mix into a stream of an inert gas such as nitrogen. During injection it is desirable to vary the flow of the powdered magnesium being injected from a no-flow to a 100-percent flow condition and back to a zero-flow condition in a linear manner and in such a manner that minimal turbulence will be created within the ladle it has been found that precise flow control of the magnesium will reduce the turbulence.